Bullshit arguments are bullshit.

You always have to trust the intentions and coding skills of the developers. Being open-source just minimizing the trust. I do consider a host variety of software to be trustless, but if I notice suspicious activity, then I'm packing my things and leaving. After seeing "privacy advocates" doxxing their competitors, funding what they're supposedly fighting against, people on the Internet accusing they've been de-anonymized by the said software, and seeing myself coinjoins with address reuse, then I don't have to study your codebase to make up my mind.